The Wave Energy Converter (WEC) has been known for many years, it was only during the last decade and a half or so that serious efforts were initiated towards exploiting it commercially. Several ocean wave energy conversion devices have since been developed, but only a few matured to full-scale trial stage, but none yet implemented fully on a commercial scale. The main disadvantage of the wave power is the uneconomical cost of extracting wave energy.
Although several Wave Energy Converters (WEC) and more than 1000 patents exist, none seem to have come up to the expectations. A truly economical and practicable solution is yet to be found. The major challenges with the state of the art WEC's have been their complexity and survivability, mainly due to the vagaries and harshness of the ocean. Solutions to such problems are being sought through improving the sophistication of the devices and making them more robust. This might improve the energy efficiency but not cost effectiveness—in terms of cost/kW, of the systems. Most importantly, none of the WEC today can perhaps be implemented with the resources readily available. They generally work with specialized and propriety technologies. Consequently, this approach increases the degree of difficulty in design, implementation, operations and maintenance of the equipment; which is quite contrary to what is required. As such, the state of the art WEC's are commercially unviable.
The World Energy Council estimates that 2 TW of energy could be harvested from the world's oceans, the equivalent of twice the world's electricity production. However, since waves are neither steady nor concentrated enough it has not yet been possible to extract and supply wave energy viably. The major problem with designing wave energy converters has been in handling the vast range of power variations in the ocean waves, from approximately average of 50 kW/m, peaking to 10 MW/m (a 1:200 ratio).
Further the focus has mostly been on improving efficiency of the devices—through ever more sophistication. As such, the state of the art, wave energy converters (WEC's) have become highly sophisticated, specialized and propriety technologies. This translates into cost escalation, besides increasing the degree of difficulty in implementation and maintenance. Most importantly, it is unlikely that of any WEC of today, can be implemented with generic resources. The devices might be highly sophisticated, even more energy efficient, but perhaps, not as cost effective—in terms of cost/kW.
Hence, a truly cost effective and simpler solution, which also offers a high degree of survivability, ease of implementation and maintenance, was required.
The present invention could possibly be the simplest and most cost effective solution, to the vexing problem of wave energy extraction and integration into the grid. As against this, the FFWEC operates on an entirely unique concept which makes it possibly the simplest and most cost effective solution yet for wave energy extraction and integration into the grid.
Most of the state of the art WEC's capture energy from the heaving motion of the waves, which is along the vertical axis. The ratio of the energy converted by most contemporary WEC's is generally a fraction of the total energy available in the wave. As against this, the FFWEC utilizes propagation of the waves along the horizontal axis.
Types of Wave Energy Converters: The state of the art power conversion devices have been generally classified into the following basic categories, namely:
Floats or Pitching Devices (Heaving buoys): These devices generate electricity from the bobbing or pitching action of a floating object. The object can be mounted to a floating raft or to a device fixed on the ocean floor. To generate large amounts of energy, a multitude of these devices must be deployed, each with its own piston and power take off equipment.
Oscillating Water Columns (OWC) These devices generate electricity from the wave-driven rise and fall of water in a cylindrical shaft. The rising and falling water column drives air in and out of the top of the shaft, powering an air-driven turbine.
Wave Surge or Focusing Devices (Overtopping): These shoreline devices, also called “tapered channel” or “tapchan” systems, rely on a shore-mounted structure to channel and concentrate the waves, driving them into an elevated reservoir. Water flow of this reservoir is used to generate electricity, using standard hydropower technologies.
Hinged Contour Converters: It is system of buoys consisting of tubular steel cylinders, attached to one another by hinges capable of interacting with a much large ocean area along its length. The force which the waves exert in moving each segment relative to its neighbors is captured by hydraulic rams that press fluid into accumulators, which, in turn, power a number of generators.
References is also made to U.S. Pat. No. 4,672,222 which provides an apparatus for producing electricity from wave motion on a body of water comprising of self stabilized and modularly expandable system of independently operative point absorbers with respective drive transmission and electrical generators.
It has, therefore, been long felt need to develop such wave energy converter, which overcomes the disadvantages of prior art, and energy is obtained at cheaper rate by simpler method and apparatus.
The present invention is quite unlike the rest of the state of the art systems. Its uniqueness lays mainly in its principle of operation, as against the rest of the state of the art WEC systems, which mostly capture energy from the undulations of waves in the vertical axis or surge, the FFWEC of the present invention extracts energy from the wave propagation in the horizontal plane.
Further, and most importantly, the FFWEC has no contacting components and moving part; besides the ‘flexible pipe(s)’ itself. Thus, the FFWEC is very simple in design, construction, operations, and easy to maintain.